1. Field of the Invention
The invention relates to a starter bar head for a continuous caster, in particular a steel strip caster, comprising a lower part capable of being introduced into the mold cavity of a continuous casting mold at least partially and on whose upper surface at least one re-entrant groove is provided, at least one connection element having a projection reaching into the mold cavity and formed of two superimposed plates, the upper plate being provided with the projection, which connection element is fastenable to the lower part and is connectable with the cast strand by casting-on, and a sealing mat of refractory material whose peripheral edge is placeable into contact with the mold side walls.
2. Description of the Related Art
A starter bar head of this type is known from EP-A-0 234 299. With this known starter bar head, the sealing mat of refractory material is inserted between the connection element and the upper surface of the lower part. The connection element is clampable relative to the lower part by means of screws, thus fixing the sealing mat. The screws, with their heads, are inserted in transverse grooves extending transverse over the upper surface of the lower part, and pass through the sealing mat and the connection element. On the screw bolts of the screws projecting beyond the upper side of the connection element, nuts are screwed, by aid of which the connection element is clampable relative to the lower part.
When casting on, the nuts weld both with the screw bolts and with the cast strand, loosening of the screw connections, thus, being no longer possible. In order to be able to separate the starter bar or starter bar head from the cast strand, it is necessary to drive the screw heads laterally out of the transverse grooves, which, however, is feasible only by applying excessive force--depending on the clamping force applied by each of the nuts. Driving out of the screw heads from the transverse grooves involves the danger of damaging the transverse grooves, which precludes the repeated use of the starter bar head, i.e., of its lower part.
Moreover, jamming of the screw heads within the grooves may result from thermal stresses and thermal expansions of the connection element such that the screw heads can be driven out of the transverse grooves only by exerting force, if at all.
A further disadvantage of the known construction is to be seen in that the preparation of the starter bar head, i.e., providing the lower part with a sealing mat and a connection element, must be carried out directly at the starter bar and hence in the casting hall.